‘More Room in a Broken Heart’ by Stephen Davis

You won’t find a more half-hearted book endorsement than the one on the back jacket of “More Room in a Broken Heart: The True Adventures of Carly Simon,’’ Stephen Davis’s new biography of the renowned singer-songwriter.

Lifted from a Boston Globe Magazine interview last year, Simon is quoted as saying: “I know the author, so there’s some integrity. He’s interviewed me over the years; he knows my family. He’s a good guy.’’